since u already have the headliner out, you can definately DIY...
find a garage, it'll be very helpul to have alot of space, the sunroof is super easy to remove. Your goin to remove it with the tracks attached. Remember to remove the water drain lines.
I don't know how much of this you have tried, but all you really need for this job is a socket wrench and a couple of sockets.
It sounds like your motor is bad....you can buy a new one on eBay for cheap (or a junkyard/lkqonline.com)
while you wait for the new motor, you can manually "force" the glass to it's most forward/closed position...
after you get it closed, re-install the sunroof assembly, but don't waste your time w/ the headliner the motor you ordered comes in, unless you just decide to leave it closed and not re-order a new motor, then your done!
eBay link to sunroof motor